Vessel sealing and dissection with controlled gap

Abstract

A forceps includes one or more shafts having first and second jaw members at the distal end portions thereof. The jaw members are moveable from a position wherein the jaw members are spaced relative to one another to one or more approximated positions wherein the jaw members cooperate to grasp and/or seal tissue. A stop member is disposed on the first jaw member and complements a corresponding step feature defined within the second jaw member. The jaw members are tip biased at their distal surfaces such that when the jaw members move from the spaced position to a first approximated position, the distal surfaces cooperate to grasp tissue. The jaw members are further movable from the first approximated position to a second approximated position wherein the stop member bottoms out within the step feature and biases the distal surfaces to form a gap therebetween for sealing purposes.

What is claimed is: 
     
         1 . A forceps, comprising:
 at least one shaft having an end effector attached at a distal end thereof, the end effector including first and second jaw members, at least one jaw member moveable about a pivot relative to the other jaw member from a position wherein the first and second jaw members are spaced relative to one another to one or more approximated positions wherein the first and second jaw members cooperate to grasp or seal tissue, each jaw member including a distal tissue engaging surface and a proximal tissue engaging surface; and   a stop member disposed on the first jaw member and extending therefrom, the stop member configured to complement a corresponding step feature defined within the second jaw member,   wherein the first and second jaw members are tip biased at the distal tissue engaging surfaces such that when the first and second jaw members move from the spaced position to a first approximated position, the distal tissue engaging surfaces of the first and second jaw members cooperate to engage tissue for grasping or dissection, and   wherein when the first and second jaw members are further moved from the first approximated position to a second approximated position, the stop member bottoms out within the step feature and biases the distal tissue engaging surfaces of the first and second jaw members to form a gap therebetween for sealing purposes.   
     
     
         2 . The forceps according to  claim 1  wherein at least one of the distal tissue engaging surfaces of at least one of the jaw members includes a mechanical feature to facilitate dissection or grasping. 
     
     
         3 . The forceps according to  claim 2  wherein the mechanical feature is selected from a group consisting of ridges, teeth, tapering, bulbous tips, and contoured outer peripheral surfaces. 
     
     
         4 . The forceps according to  claim 1  wherein when the forceps is disposed in the first approximated position, the opposing distal tissue engaging surfaces of the first and second jaw members contact one another at least at the respective distal ends thereof. 
     
     
         5 . The forceps according to  claim 1  wherein when the forceps is disposed in the first approximated position, the opposing proximal tissue engaging surfaces of the first and second jaw members include a gap defined therebetween. 
     
     
         6 . The forceps according to  claim 1  wherein when the forceps is disposed in the first approximated position, the stop member is configured to partially engage the step feature. 
     
     
         7 . The forceps according to  claim 1  wherein at least one of the first and second jaw members is adapted to couple to an energy source for sealing tissue. 
     
     
         8 . The forceps according to  claim 1  further comprising:
 first and second shaft members, each of the first and second shaft members supports a corresponding one of the first and second jaw members at a respective distal end portion thereof; and 
 a ratchet disposed on one of the first and second shaft members configured to maintain the jaw members in the second approximated position under a sealing pressure. 
 
     
     
         9 . The forceps according to  claim 8  wherein the ratchet maintains the sealing pressure between first and second jaw members within the range of about 3 kg/cm 2  to about 15 kg/cm 2 . 
     
     
         10 . The forceps according to  claim 8  wherein the other of the first and second shaft members includes a complementary mechanical interface that cooperates with the ratchet to maintain the first and second jaw members in the second approximated position. 
     
     
         11 . The forceps according to  claim 1  wherein the gap between the distal tissue engaging surfaces when the first and second jaw members are disposed in the second approximated position is within the range of about 0.001 inches to about 0.006 inches. 
     
     
         12 . The forceps according to  claim 1  wherein the stop member is configured to create a first gap between distal tissue engaging surfaces and a second gap between proximal tissue engaging surfaces when the first and second jaw members are disposed in the second approximated position. 
     
     
         13 . The forceps according to  claim 12  wherein the first gap and the second gap are different. 
     
     
         14 . The forceps according to  claim 12  wherein the first gap and the second gap are the same. 
     
     
         15 . The forceps according to  claim 1  further comprising:
 a pair of first and second shaft members, each of the first and second shaft members supporting a respective first and second jaw member at a distal end portion thereof; and 
 a switch disposed on one of the first and second shaft members and a contact disposed on the other of the first and second shaft members, the switch and the contact cooperating to energize at least one of the first and second jaw members upon engagement thereof. 
 
     
     
         16 . The forceps according to  claim 15  wherein movement of the first and second shaft members relative to one another correspondingly moves the first and second jaw members relative to one another from the spaced apart position to the first and second approximated positions and wherein engagement of the switch and the contact occurs after the first and second shaft members are squeezed and the first and second jaw members are moved beyond the second approximated position. 
     
     
         17 . A forceps, comprising:
 a first shaft member and a second shaft member, each of the first and second shaft members having a jaw member disposed at a distal end portion thereof, the first and second shaft members moveable relative to one another to correspondingly move the first and second jaw members about a pivot from a position wherein the first and second jaw members are spaced relative to one another to one or more approximated positions wherein the first and second shaft jaw members cooperate to grasp or seal tissue, each jaw member including a distal tissue engaging surface and a proximal tissue engaging surface;   a stop member disposed on the first jaw member and extending therefrom, the stop member configured to complement a corresponding step feature defined within the second jaw member,   wherein the first and second jaw members are tip biased at the distal tissue engaging surfaces such that when the first and second jaw members are moved from the spaced position to a first approximated position, the distal tissue engaging surfaces of the first and second jaw members cooperate to engage tissue for grasping or dissection, and   wherein when the first and second jaw members are further moved from the first approximated position to a second approximated position, the stop member bottoms out within the step feature and biases the distal tissue engaging surfaces of the first and second jaw members to form a gap therebetween for sealing purposes.   
     
     
         18 . The forceps according to  claim 17  wherein the gap between the distal tissue engaging surfaces when the first and second jaw members are disposed in the second approximated position is within the range of about 0.001 inches to about 0.006 inches. 
     
     
         19 . The forceps according to  claim 17  wherein the stop member is configured to create a first gap between distal tissue engaging surfaces and a second gap between proximal tissue engaging surfaces when the first and second jaw members are disposed in the second approximated position. 
     
     
         20 . The forceps according to  claim 19  wherein the first gap and the second gap are different.